Emerging E. coli Strain Causes Many Antimicrobial-Resistant Infections in U.S.

07/30/2010

A new, drug-resistant strain of E. coli is causing serious disease, according to a new study, now available online, in the August 1, 2010 issue of Clinical Infectious Diseases.

The new strain, ST131, was a major cause of serious antimicrobial-resistant E. coli
infections in the United States in 2007, researchers found. This strain
has been reported in multiple countries and encountered all over the
United States. In the study, researchers analyzed resistant E. coli
isolates collected during 2007 from hospitalized patients across the
country. They identified 54 ST131 isolates, which accounted for 67
percent to 69 percent of E. coli isolates exhibiting fluoroquinolone or extended-spectrum cephalosporin resistance.

“If
we could discover the sources of this strain, the transmission pathways
that allow it to spread so effectively, and the factors that have led
to its rapid emergence, we could find ways to intervene and possibly
slow or halt this strain’s emergence,” said study author James Johnson,
MD, of the VA Medical Center in Minneapolis.

In the past, highly virulent E. coli
strains usually have been susceptible to antibiotics, while highly
resistant strains have been fairly weak in terms of their ability to
cause disease. The susceptible strains were easily treated even though
they caused serious infections, while the resistant ones tended mostly
to affect only weakened or vulnerable individuals. Now, the study’s
findings suggest, the ST131 strain has appeared with a high level of
virulence and antimicrobial resistance.

“If this strain gains one
additional resistance gene,” Dr. Johnson added, “it will become almost
untreatable and will be a true superbug, which is a very concerning
scenario.”

###

Clinical Infectious Diseases is a leading journal in the field of infectious disease with a broad international readership. The journal publishes articles on a variety of subjects of interest to practitioners and researchers. Topics range from clinical descriptions of infections, public health, microbiology, and immunology to the prevention of infection, the evaluation of current and novel treatments, and the promotion of optimal practices for diagnosis and treatment. The journal publishes original research, editorial commentaries, review articles, and practice guidelines and is among the most highly cited journals in the field of infectious diseases. Clinical Infectious Diseases is an official publication of the Infectious Diseases Society of America (IDSA). Based in Arlington, Va., IDSA is a professional society representing more than 9,000 physicians and scientists who specialize in infectious diseases. For more information, visit www.idsociety.org.